We have done preclinical and clinical studies of automated closed systems for positive and negative selection of lymphohematopoietic cells in collaboration with biotechnology firms that have developed systems for potential application to clinical cellular therapies.Nexell, Inc. Isolex: We continued our studies of the automated Isolex 300i for immunomagnetic selection of hematopoietic progenitor cells. Starting in the previous fiscal year and going into this year, we completed 28 full-scale runs on version 1.0 of this system. We demonstrated its utility in clinical protocols for chronic granulomatous disease gene transfer and autologous transplantation of chronic ITP. We also initiated evaluation of the new version 2.0 system, completed 12 full-scale runs, and have begun development of the combined positive/negative selection procedure for T cell depletion. Preliminary results show consistent T depletion of 5 logs using this method.CellPro T Cell Depletion System: A clinical evaluation of this 2-step positive (CD34) and negative (CD2) selection system, which uses an immunoadsorption approach, was recently completed. This study randomized 24 allogeneic donors to fresh versus pooled processing of stem cell apheresis products. Results, submitted in abstract form to ASH, demonstrated equivalence between the two study arms in processing and clinical outcomes. Therefore, the pooled processing approach will be used for practical and economic reasons (less processing time, lower costs associated with use of one expensive system versus two).